A study on the relative efficacy of three antivenoms against medically significant Centruroides species from Mexico

 

Mexico is a hot spot for medical important scorpions and at least 21 species from the Centruroides Marx, 1890 (Buthidae) genus cause a large number of serious envenomations every year. Good treatment options is important and using antivenom is one of the most important tool.

Sam Campbell and co-workers have recently published a study looking into the ability of three  antivenoms to neutralize the activity of the venoms of several Centruroides species. One important result from this study is that the truly “broad” neutralization capacity of the antivenoms can be questioned as there were variations in the neutralization of several medical important Centruroides species (even though the venom of these were included in the antivenoms).

The author also stress the importance of proper laboratory studies and methods for studying the effects of antivenom candidates.

Abstract:
In this study, we report the innovative application of whole-cell patch-clamp electrophysiology in assessing broad-spectrum neutralisation by three different antivenoms, of venoms from the medically significant scorpion genus Centruroides. Envenomations by as many as 21 species from the Centruroides genus result in up to 300,000 envenomations per year in Mexico, which poses significant and potentially life-threatening pathophysiology. We first evaluated the in vitro manifestation of envenomation against two human voltage-gated sodium (hNaV) channel subtypes: hNaV1.4 and hNaV1.5, which are primarily expressed in skeletal muscles and cardiomyocytes, respectively. The neutralisation of venom activity was then characterised for three different antivenoms using a direct competition model against the more potent target, hNaV1.4. While broad-spectrum neutralisation was identified, variation in neutralisation arose for Centruroides elegans, C. limpidus, C. noxius and C. suffusus venoms, despite the presence of a number of these venoms within the immunising mixture. This raises questions regarding the truly “broad” neutralisation capacity of the antivenoms. This study not only extends previous validation of the in vitro investigation of antivenom efficacy utilising the whole-cell patch-clamp technique but also underscores the potential of this animal-free model in exploring cross-reactivity, experimental scalability, and most importantly, informing clinical management practices regarding the administration of antivenom in Mexico.

Reference:
Campbell SID, Chow CY, Neri-Castro E, Alagón A, Gómez A, Soria R, et al. Taking the sting out of scorpions: Electrophysiological investigation of the relative efficacy of three antivenoms against medically significant Centruroides species. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology. 2024;283:109977. [Open Access]

Thanks to Jeroen Kooijman for informing me about this article!